Lower Urinary Tract Symptoms (LUTS) is a progressive disorder marked by urinary frequency and urgency, decreased force of stream, incomplete bladder emptying, and nocturia which can progress to bladder dysfunction and urinary retention. LUTS is a costly and potentially critical medical problem for millions of aging American men. Data recently acquired in our laboratory shows that extracellular matrix [ECM] deposition and fibrosis characterize the peri-urethral prostate tissues of some men symptomatic for LUTS. Such fibrotic changes increase peri-urethral tissue stiffness and compromise urethral flexibility and compliance, producing urinary obstructive symptoms. Preliminary data presented in this application shows that total RNA purified from the urine of 4 men symptomatic for LUTS (American Urological Association Symptom Index Scores [AUASIs] of 16, 19, 22 and 23) and subjected to whole transcriptome amplification followed by transcript-specific qRT-PCR demonstrated ~10-fold higher levels of TGFb transcript and 2-5- fold higher levels of COL1 and aSMA transcripts compared to similarly purified and processed RNA from 4 men asymptomatic for LUTS (AUASIs of 0, 0, 1 and 3). These findings show that specific gene transcripts encoding proteins that mediate and promote tissue fibrosis can be selectively detected in the urine of men symptomatic for LUTS using novel whole transcriptome amplification techniques. Based on these findings, we now seek to test the hypothesis that peri-urethral prostatic fibrosis contributing to LUTS as assessed by moderate-severe AUASI scores may be detected by the presence of urinary biomarkers comprising specific gene transcripts encoding proteins that mediate and promote tissue fibrosis. We are fortunate to possess the expertise to recover and amplify RNA from urine as well as a large clinically well-annotated biorepository of human prostate tissues and urine specimens from men who are prostate cancer biopsy negative and are asymptomatic or symptomatic for LUTS. Utilizing these resources, we propose to test the stated hypothesis through the completion of two Specific Aims: SPECIFIC AIM 1: Determine whether RNA transcript levels from genes encoding proteins that mediate and promote tissue fibrosis are consistently and significantly higher in the urine of men self-reporting moderate/severe LUTS compared to men self-reporting absent/mild LUTS. SPECIFIC AIM 2: Determine the collagen content of prostate biopsy tissues from a subset of patients examined in Specific Aim 1 and correlate these with fibrosis biomarker levels and AUASI scores.